Direct and reverse transformations between electron density and electron momentum density: connection with the locally averaged method

Abstract

It has been established here that the direct transformation from electron density to electron momentum density [Phys. Rev. A 24, 2906 (1981)] is exactly identical to the locally averaged method of Lam and Platzman [Phys. Rev. B 9, 5128 (1974)] for a spherically symmetric, monotonic-decreasing atomic-electron density. However, the former approach brings out more clearly the physical features associated with the momentum density extracted from the electron density and also has the potential to effect reverse transformations.